Submitted to: Transactions of the ASAE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 15, 1998
Publication Date: N/A
Interpretive Summary: Many consumers rate tenderness as the most important factor in determining beef quality. Currently, tenderness is measured on cooked meat using the Warner-Bratzler (WB) shear device. To predict tenderness from raw meat, one needs to understand the mechanical properties of raw and cooked beef and their relationship with beef tenderness. The objective of this research was to measure the tensile properties of raw and cooked beef and to quantify the relationship between beef tensile properties and WB tenderness measurement. Tensile and WB shear tests were performed on raw and cooked beef from four bovine muscles. Results showed that raw and cooked beef exhibited nonlinear tensile behavior. Cooking generally produced an increase in beef tensile strength and a decrease in WB shear value. WB shear value was significantly correlated with the maximum tensile force of cooked beef from strip loin and top round muscles. Tenderness, as measured by the WB shear device, could be predicted from the tensile properties of raw beef for strip loin muscle but not for the other three muscles. This study should help researchers and engineers better understand the mechanism of WB shearing and can be valuable for developing a method to predict tenderness from raw beef.
Technical Abstract: Tensile and Warner-Bratzler (WB) shear tests were performed to study the mechanical properties of raw and cooked beef and their relationship with WB tenderness measurement. Four bovine muscles, biceps femoris (BF), longissimus dorsi (LD), semimembranosus (SM), and semitendinosus (ST), were used. Results showed that raw muscles exhibited all or some of the elastic, stress-yielding, and work-hardening behaviors in tension. Cooked beef also showed the elastic and stress-yielding behaviors but not the work-hardening behavior. Cooking resulted in a significant (p<0.05) increase in the maximum tensile force, ranging from 65% for BF muscle to 144% for SM muscle. The strain energy at break did not change significantly for BF, LD, and SM muscles after cooking but increased significantly for ST muscle. Contrarily, WB shear value decreased about 50% for BF and ST muscles after cooking, and it did not show a significant change for LD and SM muscles. Muscle type had a considerable effect on the relationship between tensile properties and WB shear measurements. The correlation between WB shear value and the maximum tensile force for cooked beef was significant for LD and SM muscles (r=0.65 and r=0.48, respectively) and was not for the other two muscles. There was also a significant correlation (r=0.64) between WB shear value of cooked beef and the maximum tensile force of raw beef for LD muscle. No correlation was found between WB shear value of raw and cooked beef for the four muscles.